Publications

@article{chtarbanova_drosophila_2014,
title = {Drosophila C virus systemic infection leads to intestinal obstruction},
author = { Stanislava Chtarbanova and Olivier Lamiable and Kwang-Zin Lee and Delphine Galiana and Laurent Troxler and Carine Meignin and Charles Hetru and Jules A. Hoffmann and Laurent Daeffler and Jean-Luc Imler},
url = {http://jvi.asm.org/content/88/24/14057},
doi = {10.1128/JVI.02320-14},
issn = {1098-5514},
year = {2014},
date = {2014-12-01},
journal = {Journal of Virology},
volume = {88},
number = {24},
pages = {14057--14069},
abstract = {Drosophila C virus (DCV) is a positive-sense RNA virus belonging to the Dicistroviridae family. This natural pathogen of the model organism Drosophila melanogaster is commonly used to investigate antiviral host defense in flies, which involves both RNA interference and inducible responses. Although lethality is used routinely as a readout for the efficiency of the antiviral immune response in these studies, virus-induced pathologies in flies still are poorly understood. Here, we characterize the pathogenesis associated with systemic DCV infection. Comparison of the transcriptome of flies infected with DCV or two other positive-sense RNA viruses, Flock House virus and Sindbis virus, reveals that DCV infection, unlike those of the other two viruses, represses the expression of a large number of genes. Several of these genes are expressed specifically in the midgut and also are repressed by starvation. We show that systemic DCV infection triggers a nutritional stress in Drosophila which results from intestinal obstruction with the accumulation of peritrophic matrix at the entry of the midgut and the accumulation of the food ingested in the crop, a blind muscular food storage organ. The related virus cricket paralysis virus (CrPV), which efficiently grows in Drosophila, does not trigger this pathology. We show that DCV, but not CrPV, infects the smooth muscles surrounding the crop, causing extensive cytopathology and strongly reducing the rate of contractions. We conclude that the pathogenesis associated with systemic DCV infection results from the tropism of the virus for an important organ within the foregut of dipteran insects, the crop. IMPORTANCE: DCV is one of the few identified natural viral pathogens affecting the model organism Drosophila melanogaster. As such, it is an important virus for the deciphering of host-virus interactions in insects. We characterize here the pathogenesis associated with DCV infection in flies and show that it results from the tropism of the virus for an essential but poorly characterized organ in the digestive tract, the crop. Our results may have relevance for other members of the Dicistroviridae, some of which are pathogenic to beneficial or pest insect species.},
keywords = {bioinformatic, Dicistroviridae, Female, Gastrointestinal Tract, Gene Expression Profiling, Intestinal Obstruction, Muscle, Nodaviridae, Sindbis Virus, Smooth, Viral Tropism},
pubstate = {published},
tppubtype = {article}
}

@article{deleury_specific_2012,
title = {Specific versus non-specific immune responses in an invertebrate species evidenced by a comparative de novo sequencing study},
author = { Emeline Deleury and Géraldine Dubreuil and Namasivayam Elangovan and Eric Wajnberg and Jean-Marc Reichhart and Benjamin Gourbal and David Duval and Olga Lucia Baron and Jérôme Gouzy and Christine Coustau},
doi = {10.1371/journal.pone.0032512},
issn = {1932-6203},
year = {2012},
date = {2012-01-01},
journal = {PLoS ONE},
volume = {7},
number = {3},
pages = {e32512},
abstract = {Our present understanding of the functioning and evolutionary history of invertebrate innate immunity derives mostly from studies on a few model species belonging to ecdysozoa. In particular, the characterization of signaling pathways dedicated to specific responses towards fungi and Gram-positive or Gram-negative bacteria in Drosophila melanogaster challenged our original view of a non-specific immunity in invertebrates. However, much remains to be elucidated from lophotrochozoan species. To investigate the global specificity of the immune response in the fresh-water snail Biomphalaria glabrata, we used massive Illumina sequencing of 5'-end cDNAs to compare expression profiles after challenge by Gram-positive or Gram-negative bacteria or after a yeast challenge. 5'-end cDNA sequencing of the libraries yielded over 12 millions high quality reads. To link these short reads to expressed genes, we prepared a reference transcriptomic database through automatic assembly and annotation of the 758,510 redundant sequences (ESTs, mRNAs) of B. glabrata available in public databases. Computational analysis of Illumina reads followed by multivariate analyses allowed identification of 1685 candidate transcripts differentially expressed after an immune challenge, with a two fold ratio between transcripts showing a challenge-specific expression versus a lower or non-specific differential expression. Differential expression has been validated using quantitative PCR for a subset of randomly selected candidates. Predicted functions of annotated candidates (approx. 700 unisequences) belonged to a large extend to similar functional categories or protein types. This work significantly expands upon previous gene discovery and expression studies on B. glabrata and suggests that responses to various pathogens may involve similar immune processes or signaling pathways but different genes belonging to multigenic families. These results raise the question of the importance of gene duplication and acquisition of paralog functional diversity in the evolution of specific invertebrate immune responses.},
keywords = {Biomphalaria, Calmodulin, Cluster Analysis, Complementary, DNA, Expressed Sequence Tags, Ferritins, Gene Expression Profiling, Gene Expression Regulation, High-Throughput Nucleotide Sequencing, Immunity, Innate, Messenger, Pattern Recognition, Phylogeny, Receptors, RNA, Signal Transduction, Zinc Fingers},
pubstate = {published},
tppubtype = {article}
}

@article{roetzer_candida_2008b,
title = {Candida glabrata environmental stress response involves Saccharomyces cerevisiae Msn2/4 orthologous transcription factors},
author = { Andreas Roetzer and Christa Gregori and Ann Marie Jennings and Jessica Quintin and Dominique Ferrandon and Geraldine Butler and Karl Kuchler and Gustav Ammerer and Christoph Schüller},
doi = {10.1111/j.1365-2958.2008.06301.x},
issn = {1365-2958},
year = {2008},
date = {2008-01-01},
journal = {Mol. Microbiol.},
volume = {69},
number = {3},
pages = {603--620},
abstract = {We determined the genome-wide environmental stress response (ESR) expression profile of Candida glabrata, a human pathogen related to Saccharomyces cerevisiae. Despite different habitats, C. glabrata, S. cerevisiae, Schizosaccharomyces pombe and Candida albicans have a qualitatively similar ESR. We investigate the function of the C. glabrata syntenic orthologues to the ESR transcription factor Msn2. The C. glabrata orthologues CgMsn2 and CgMsn4 contain a motif previously referred to as HD1 (homology domain 1) also present in Msn2 orthologues from fungi closely related to S. cerevisiae. We show that regions including this motif confer stress-regulated intracellular localization when expressed in S. cerevisiae. Site-directed mutagenesis confirms that nuclear export of CgMsn2 in C. glabrata requires an intact HD1. Transcript profiles of CgMsn2/4 mutants and CgMsn2 overexpression strains show that they regulate a part of the CgESR. CgMsn2 complements a S. cerevisiae msn2 null mutant and in stressed C. glabrata cells, rapidly translocates from the cytosol to the nucleus. CgMsn2 is required for full resistance against severe osmotic stress and rapid and full induction of trehalose synthesis genes (TPS1, TPS2). Constitutive activation of CgMsn2 is detrimental for C. glabrata. These results establish an Msn2-regulated general stress response in C. glabrata.},
keywords = {Candida glabrata, Candidiasis, DNA-Binding Proteins, Fungal, Fungal Proteins, Gene Expression Profiling, Gene Expression Regulation, Genetic, Humans, Oligonucleotide Array Sequence Analysis, Osmotic Pressure, Regulon, Saccharomyces cerevisiae Proteins, Transcription, Transcription Factors, Virulence, Yeasts},
pubstate = {published},
tppubtype = {article}
}

@article{irving_new_2005,
title = {New insights into Drosophila larval haemocyte functions through genome-wide analysis},
author = { Phil Irving and Jean-Michel Ubeda and Daniel Doucet and Laurent Troxler and Marie Lagueux and Daniel Zachary and Jules A. Hoffmann and Charles Hetru and Marie Meister},
doi = {10.1111/j.1462-5822.2004.00462.x},
issn = {1462-5814},
year = {2005},
date = {2005-03-01},
journal = {Cell. Microbiol.},
volume = {7},
number = {3},
pages = {335--350},
abstract = {Drosophila blood cells or haemocytes comprise three cell lineages, plasmatocytes, crystal cells and lamellocytes, involved in immune functions such as phagocytosis, melanisation and encapsulation. Transcriptional profiling of activities of distinct haemocyte populations and from naive or infected larvae, was performed to find genes contributing to haemocyte functions. Of the 13 000 genes represented on the microarray, over 2500 exhibited significantly enriched transcription in haemocytes. Among these were genes encoding integrins, peptidoglycan recognition proteins (PGRPs), scavenger receptors, lectins, cell adhesion molecules and serine proteases. One relevant outcome of this analysis was the gain of new insights into the lamellocyte encapsulation process. We showed that lamellocytes require betaPS integrin for encapsulation and that they transcribe one prophenoloxidase gene enabling them to produce the enzyme necessary for melanisation of the capsule. A second compelling observation was that following infection, the gene encoding the cytokine Spatzle was uniquely upregulated in haemocytes and not the fat body. This shows that Drosophila haemocytes produce a signal molecule ready to be activated through cleavage after pathogen recognition, informing distant tissues of infection.},
keywords = {bioinformatic, Catechol Oxidase, Cell Lineage, Enzyme Precursors, Escherichia coli, Fat Body, Gene Expression Profiling, Genome, Hemocytes, Integrin alpha Chains, Integrins, Larva, Micrococcus luteus},
pubstate = {published},
tppubtype = {article}
}

@article{kambris_tissue_2002,
title = {Tissue and stage-specific expression of the Tolls in Drosophila embryos},
author = { Zakaria Kambris and Jules A. Hoffmann and Jean-Luc Imler and Maria Capovilla},
issn = {1567-133X},
year = {2002},
date = {2002-12-01},
journal = {Gene expression patterns: GEP},
volume = {2},
number = {3-4},
pages = {311--317},
abstract = {The Drosophila transmembrane receptor Toll plays a key role in specifying the dorsoventral axis of the embryo. At later stages of development, it controls the immune response of the fly to fungal and Gram-positive bacterial infections. The Drosophila genome has a total of nine Toll-like genes, including the previously characterized Toll (Toll-1) and 18-wheeler (Toll-2). Here we describe the embryonic expression patterns of the seven Toll-like genes Toll-3 through Toll-9. We find that these genes have distinct expression domains and that their expression is dynamically changing throughout embryonic development. This complex and tissue-specific regulation of Toll-like gene expression strongly suggests a role in embryonic development for most Drosophila Tolls. The evolving picture on the Toll family members in Drosophila contrasts with that of mammalian Toll-like receptors, which are predominantly expressed in immune responsive cells where their activation occurs via microbial structural determinants.},
keywords = {Blotting, Cell Surface, Gene Expression Profiling, Larva, Multigene Family, Northern, Receptors, Toll-Like Receptors},
pubstate = {published},
tppubtype = {article}
}